1. Field of the Invention
The present invention relates to an optical disk player, an audio signal output device, and an AV system which output audio signals to an audio output amplifier through an HDMI (High-Definition Multimedia Interface) cable.
2. Description of the Related Art
Conventionally, audio signals which are sampled at 44.1 kHz of sampling frequency are recorded in an audio CD (Compact Disk). Recently, with generalization of optical disks such as a high-capacity DVD (Digital Versatile Disk) and so on, audio signals are sampled at high sampling frequency of 48 kHz, 96 kHz, or 192 kHz and recorded in the optical disc so as to meet needs for further high-quality sound. The optical disk players are conventionally adapted to play the audio signals which are recorded at various sampling frequencies as described above.
Moreover, the optical disk players in recent years are constituted to produce a surround sound effect when a plurality of speakers equal to or more than four are connected thereto through an audio output amplifier which supports multi-channels. The optical disk player is normally connected to the audio output amplifier through an HDMI (High-Definition Multimedia Interface) cable.
Japanese Laid-Open Patent Publication No. 2001-306097 discloses an audio coding device which performs a down-sampling of sub-band signals of a frequency in each band corresponding to output sub-band signals Furthermore, Japanese Laid-Open Patent Publication No. 2002-74828 discloses a DVD player which outputs audio signals with being down-sampled to have 48 kHz of sampling frequency, in case that the audio signals are scrambled. On the other hand, Japanese Laid-Open Patent Publication No. 2003-208200 discloses a signal playing method to convert a sampling frequency of received compressed data according to its playable time.
However, some audio output amplifiers distributed to the market do not support the high sampling frequency of 48 kHz, 96 kHz, and 192 kHz, and thus, when audio signals, having a sampling frequency which is not supported, are inputted to such an audio output amplifier, a problem arises that a playing can not appropriately be carried out due to the occurrence of noises or skipping of sound.